Tour de France Bikes 2015: Luke Rowe’s Pinarello Dogma K8-S ready for the cobbles

The Tour de France encounters the pave of Belgium today with seven sectors of cobbles totaling 13.3km, which doesn’t sound like a lot in a 223.5km stage - the Tour’s longest - but that hasn’t stopped the teams from preparing its Paris-Roubaix special bikes for the stage.

Team Sky will roll out on the new Pinarello Dogma K8-S, which debuted at that race back in April, and features a suspension damper at the top of the seatstays designed to isolate, to an extent, the rider from the vibrations caused by the cobbles. Pinarello claims the new Dogma K8-S can boost rider comfort by as much as 50% compared to a regular bike.

This bike belongs to Luke Rowe, who will doubtless be working hard over the cobbles to help Chris Froome defend the yellow jersey, but just as critically marshalling Froome safely and cleanly over the cobbles which are heaped up towards the end of this long stage. The whole team obviously wants to avoid a repeat of last year’s crash which put the Tour contender out of the race.

In designing the new Dogma K8-S, the Italian bicycle company has developed a small suspension unit that sits at the top of the seatstays. It houses a piston and elastomer bumper that can be tuned for rider weight and softness preference. There are no pivots in the rear triangle, instead Pinarello has modified the carbon fibre layup in the chainstays, flat and wide towards the dropouts, that provide the desired range of flex to make the whole thing work.

The concept isn’t a new one. The idea of flexible carbon fibre stays was used quite widely on early mountain bikes, with companies like Trek and Cannnondale both at one point offering soft tail mountain bikes. There were a few road versions, most famously Trek's brief flirtation with a soft tail race bike for the Discovery team, but that ended soon after George Hincapie's ill-fated Paris-Roubaix, when the steerer tube on his bike snapped.

Along with the new damper unit, Pinarello has also developed a new aero seatpost that it reckons provides up to 40% more absorption of vertical forces.

The Dogma K8-S frame is equipped with much the same kit as Luke Rowe’s regular Dogma F8 road bike, with a Shimano Dura-Ace Di2 groupset providing the shifting and braking, with the optional Di2 sprint shifters. The cassette is an 11-25t item, as Paris-Roubaix, and today’s stage of the Tour de France, feature virtually no climbing.

There are some notable detail changes though. He’s using a chainset with a 53/44t chainring combination, instead of the regular 53/39t setup - that’s because the stage is mostly flat and 39t is simply too low, but the 44t provides a smaller step down from the big ring if he needs it. Luke Rowe also uses long 175mm crank arms rather than the more common 172.5mm.

Wheels are Shimano Dura-Ace C50 carbon fibre tubular tyres, pretty standard fare, but they’re fitted with FMB Paris-Roubaix 27mm tyres, the same rubber the team uses in the Paris-Roubaix. Because of course this is the same bike and set up used for that race.

The Elite bottle cages have a grippy tape material added to prevent the water bottles ejecting.

It looks like he has a double wrap of PRO bar tape on the aluminium PRO handlebars.

His stem is an aluminium PRO product too, in a 141mm length.

A Fizik Arione saddle in all-black with white marks, there to help the mechanics set up the correct saddle position. Each bike in the Team Sky truck had the same white marks, suggesting they have developed a precise system for replicating saddle position across different bikes.

Of course Team Sky has a neat way of fixing the race number boards to the bike. The small mount is glued to the seatpost, with two Allen bolts to secure the number plate. No zip ties here.

See more Tour de France bikes here.